Automatic drill pipe elevator



May 9, 1950 M- E. TRUE AUTOMATIC DRILL PIPE ELEVATOR Filed Dec. 27/ 1948 2 She'ecs-Sheet 1 Fl G. 2.

ATTORNEY.

M. E. TRUE AUTOMATIC DRILL PIPE ELEVATOR May 9, 1950 2 Sheets-Sheet 2 Filed Dec. 27, 1948 Is 1/, Mi

FIG.

INVENTOR MW: @Qbfi ATTORNEY.

Patented May 9, 1950 UNITED STATES PATENT OFFICE AUTOMATIC DRILL PIPE ELEVATOR Delaware Application December 27, 1948, Serial No. 67,368 4 Claims. (Cl. 294-88) The present invention is directed to a device for engaging with a tubular structure and for supporting it and for moving it from one position to another. More particularly, the device of the present invention is adapted for handling vertical sections of pipe in the drilling of a borehole.

When moving a vertical or substantially vertical tubular structural member from one position to another, it may be desirable or necessary to provide means for engaging with the tubular member for suspending it during the operation. An example of such an operation is the handling of sections of drill pipe in a derrick during the drilling of a borehole. In such an operation a derrick is mounted over the borehole and is arranged for suspending the drill stem or sections of pipe used to make up the drill tem. The conventional hoisting mechanism employed includes a crown block, a drilling line having one end secured to a hoisting drum and suspending a travelling block from the crown block, a hook carried by the travelling block and an elevator suspended from the hook for engaging and disengaging with the end sections of drill pipe. Conventional elevators are arranged to be engaged with an external shoulder at the upper end of the length of pipe to be handled, the engagement of the elevator with the shoulder being accomplished manually. Inasmuch as the crown block, hook and elevator are of tremendous weight and further, as it is often dimcult for the driller to bring the elevator to rest at the proper point just below the shoulder of the drill pipe section to be grasped, the engagement of the elevator with the shoulder is accomplished in some cases only with difllculty. The danger to personnel working in close proximity to suspended weights of such magnitude is obvious. The disengagement of a section of drill stem from the conventional elevator is also accompanied by serious disadvantages when, for example, a section of pipe has been disengaged from the remaining portion of the drill stem it must be set on the derrick floor at a point removed from the center of the derrick. Furthermore, after such a section has been placed on-the floor at the desired point, the elevator must be disengaged manually by personnel stationed at a point near the top of the derrick opposite the upper end of the drill pipe. The danger to personnel and the inconvenience of such a method are obvious.

It is an object of the present invention to provide an assembly adapted to engage releasably with the external shoulder of a tubular structure.

It is a further object of the present invention to provide a structure which will releasably engage with the external shoulder of a tubular member and which will suspend the member in a vertical position.

Other objects and advantages of the present invention may be seen from the following description taken in conjunction with the drawing in which Fig. 1 is an elevation, partly in cross-section, showing an embodiment of the present invention with the parts in position for engaging with }the shoulder at the upper end of a tubular mem- Fig. 2 is an elevation, partly in cross-section, showing an embodiment of the present invention with the parts thereof engaged with the shoulder of the upper end of a tubular member;

Fig. 3 is a sectional view taken along line III-III of Fig. 2;

Fig. 4 is a sectional view taken along line IV-IV of Fig. 1; and

Fig. 5 is a sectional perspective View of the slip assembly removed from the embodiment of the present invention.

The device of the present invention may be described briefly as an assembly capable of automatically engaging with the shoulder at the end of a tubular member. The device is arranged so as to be disengageable from the shoulder by remote control. When engaged with a tubular member, the device permits rotation between the engaged member and the point at which the assembly is suspended from the travelling block.

For convenience, the device shown in the drawing has its principal parts or assemblies designated by letters and the component parts of the principal parts designated by numerals. The embodiment shown in the drawing includes as principal parts slip assembly A, slip bowl assembly B, body C, suspending assembly D, trigger assembly E, and tension member F.

Briefly, in the device of the present invention slip assembly A is adapted to assume an expanded state when disengaged from the shoulder of a tubular member and a contracted state when it is engaged with the shoulder of a tubular member. In Fig. 1 a slip assembly A is shown in its expanded state while in Fig. 2 the slip assembly is shown in its contracted state. Slip bowl assembly B is arranged to assume a first position which allows slip assembly A to assume an expanded state and a second position which forces slip assembly A to assume its contracted state. Slip assembly 3 is shown in its first position in Fig. 1 and in its second position in Fig. 2. suspending assembly D is arranged slidably on tension member F for limited movement along the longitudinal axis of the said tension member. Trigger assembly E is arranged to assume a first position when slip assembly A is in its expanded state and a second position when slip assembly A is in its contracted state.

Body assembly C is tubular in shape, open at its lower end and closed at its upper end by a head having an opening adapted to receive tension member F. Slip assembly A, slip bowl assembly B and trigger assembly E are disposed within body assembly C.

The construction of the device shown in the drawing will now be described in detail.

Body assembly C consists of tubular wall portion II with closure plate |2 defining port l3 mechanically aflixed to the upper end of tubular wall portion The center of port I3 coincides with the longitudinal axis of tubular wall portion ll. Tension member F passes through port |3 being rigidly aflixed thereto, the lower portion of said member extending into the space defined by tubular wall portion I I and the upper portion extending upwardly above plate l2. The upper extremity of tension member F is mechanically connected with ring guide H which is adapted to move slidably within suspending assembly D.

Suspending assembly D consists of a head l5 which defines a hole l6 for engaging with a hook (not shown) for suspending the assembly. Head I5 is mechanically affixed to tubular body portion l1. Tubular body portion I1 is closed at its lower end l8 which defines port I9 at the radial center thereof. Tension member F passes slidably through port l9, its upward vertical movement with respect to suspending assembly D being limited by the abutment of ring I4 against head l5 and its downward vertical motion being limited by the abutment of guide ring l4 against the lower end I8 of tubular body l'l.

Slip bowl assembly B consists of slip bowl 20, piston 2| and piston guide 22, piston guide 22 mechanically connecting piston 2| with slip bowl 20. Slip bowl is arranged to move slidably with respect to the internal surface of tubular portion l I of body assembly 0. Piston 2| is arranged to move slidably with respect to tubular portion H in sealing contact therewith. A sealing means, such as sealing rings 2|, may be provided in the cylindrical surface of piston 2| to provide a relatively fluid-tight seal between piston 2| and wall ll. Ring 23 is rigidly affixed to tubular wall below port H which traverses tubular wall portion Ring 23 is also in sealing contact with piston guide 22 so as to prevent the passage of fluid from the space above ring 23 to the space below ring 23 upon longitudinal movement of piston guide 22. A sea ing means, such as rings 23', are carried by ring 23 so as to provide a relatively fluid-tight seal between ring 23 and piston guide 22. Spring 24 encircles piston guide 22 and exerts a bias upwardly against ring 23 and downwardly against slip bowl 20.

The outer surface of slip bowl 20 is in the form of a cylinder. The upper end of slip bowl 20 is closed by means of plate 25 defining in its center portion threaded port 26, threadedly engageable' with the threaded portion of the lower end of piston guide 22. The inner wall surface of slip bowl 20 is, for a portion of its length, in the form of a cylindrical surface. In the lower portion of the aforementioned cylindrical surface is ball groove 21. Just below ball groove 21 the inner surface 50 of slip bowl 20 tapers outwardly and downwardly forming a conical surface which terminates at the lower end of slip bowl 28.

Slip assembly A is made up of a plurality of members 28 hereinafter designated as slips. Each slip has an interior surface 33 terminating in a lip 3| adapted to engage with the shoulder of a tubular member for suspending said member and an outer face 38 adapted to be slidably arranged with inner surface 50 of slip bowl 20. The several slips 28 are bonded together to form a unit by a deformable structural material 29. It will usually be preferred to' use an oil resistant synthetic rubber as the deformable structural material 29. Any one of several synthetic rubber products may be used for this purpose. It will be obvious, of course, that other deformable structural material, such as natural rubber, may be employed. For convenience, deformable structural material 29 will hereinafter be referred to as rubber. For ease of construction, it will generally be desirable. to form the entire slip assembly as a unita'y structure by using a suitable mold, placing segments 28 radially therein in the position they are to occupy in the completed assembly, forming the unvulcanized rubber around the segments so that inner surface 33 and outer surface 36 project radially a slight distance beyond the rubber so that the completed assembly has the appearance as shown in Figs. 3 and 4. It will be noted from Fig. 3 that the rubber is so formed in the mold that slips 28 project above the upper edge of the rubber and below the lower edge of the rubber. It will be understood, of course, that while the exact form given to the rubber is not critical, the rubber should be formed in the molds so that it does not interfere with the longitudinal movement of the completed assembly or with the engagement of shoulders 39 by lip 3|. After the rubber has been formed in the mold, the rubber is vulcanized so that it will permanently retain its molded shape except when it is deformed when lip 3| is engaged with shoulder 30 of a tubular member for suspending said member. It will be noted from Fig. 5 that when slips 28 and deformable structural material 29 are formed into assembly A and the assembly is in its normal state, the outer surfaces 36 of slips 28 define for at least a portion of their height a frustum of a cone. Inner surface 33 terminates at its lower end at inwardly extending lip 3|, the said lip being adapted to engage with shoulder 30 of a tubular member. Below lip 3| the lower edges of slips 28 taper downwardly and outwardly to form tapered surface 35 which terminates on its juncture with outer surface 36. Slips 28 further define at their upper extremity inwardly extending supporting ledge 31, the said ledge defining longitudinal slots 38 along the inner periphery thereof.

Fig. 2 shows lip 3| in engagement with shoulder 30 of a suspended tubular member, assembly A having been forced into the engaging position by the wedging action supplied by the downward movement of slip bowl assembly B. It will be noted that when slip assembly A is in the engaged position shown, the inner surface of slip assembly A formed by surface 33 of slips 28 is substantially parallel to outer surface 34 of tubular member 32. It will be further noted that outer surface of slip assembly A formed by outer surface 36 of slips 28 is in contact with the inner surface 58 of slip bowl assembly B. The down- 76 ward and outward taper of surface 36 is substantially identical with the downward and outward taper of surface 60 so that when slip bowl assembly- B is moved downwardly. surface 50 thereof moves slidably in contact with outer surface 36 of slips 28. Fig. 5, a view of slip assembly A in the engaged position, shows flexible structural material 29 in its deformed condition. It will be noted from this figure that the outer and inner surfaces of the deformable material 29 in its deformed condition do not coincide with the surfaces formed by outer surface 36 and inner surface 33 of slips 28. As previously mentioned, deformable structural material 29 should be so molded as to accomplish this result in order that it will not interfere with the sliding of the surface 50 on surface 36 nor with the engagement portion 4i which is adapted to move in slidable contact with the inner cylindrical surface of slip bowl 20 between the upper and lower terminus of cylindrical inner portion thereof. On its outer cylindrical surface of cylindrical portion 4| are large annulus 45 and small annulus 46, annulus 46 being above annulus 45. Spring 43 is biased upwardly against spring sto 5i which projects radially from tension member F, and downwardly against ring portion 40 of trigger ring 39. Trigger pins 42 are adapted to pass through slots 38 of slips 28. Trigger pins 42 also are adapted to pass slidably through ports 4'! defined by trigger pin guide 41', carried by the lower extremity of tension member F. Trigger pin guide 4'! also serves to support slip assembly A inside body assembly C. When slips 28 are in the disengaged state shown in Fig. 1, trigger pins "project through ports 41 and extend below the lower edge of trigger pin guide 41', inasmuch as trigger ring 39 is biased downwardly into its lowermost position by trigger spring 43; furthermore, balls 44 are located in ball groove 21 opposite small annulus 46. When slip assembly A is in its engaged state as shown in Fig. 2, trigger pins 42 are pushed upwardly by virtue of their contact with the upper edge of tubular member 32, thereby moving trigger ring 39 upwardly until balls 44 drop into annulus 45 thereby permitting slip bowl assembly B to move downwardly. Inasmuch as inwardly extending portion 31 of slips 28 are provided with slots 38, slips 28 are free to move from their engaged position to their disengaged position and from their disengaged position to their engaged position without interfering with the vertical movement of trigger pins 42. When slip assembly A is in its disengaged state and trigger balls 44 are in the space defined by small annulus 46 and ball groove 21, slip bowl assembly B is prevented from moving either upwardly or downwardly. In this state inner surface 56 of slip bowl assembly B is out of contact with outer surface 36 of slip assembly A. When slip assembly A is in the engaged state shown in Fig. 2, ball 46 is located in the space defined by large annulus 45 where it does not prevent the downward motion of slip bowl 20, and consequently slip bowl 20 is driven downwardly by the bias exerted by spring 24 so that inner surface 50 of slip bowl 20 is in sliding contact with outer surface 36 of slip assembly A. This downward motion of slip assembly B tends to contract slip assembly A to cause slip assembly A to engage with shoulder 30 of pipe 32.

Having described in detail the various elements and combination of elements of the device of mytubular member having an outwardly extending shoulder, such as a section of drill pipe, the suspended device of my invention is lowered to thepoint immediately above the member to be suspended. Just prior to engagement with the member, slip assembly A is in the expanded stateshown in Fig. 2. At this point trigger assembly- E is in its lowermost position preventing eitherupward or downward motion of slip bowl assembly B. It will also be noted that trigger pins 42 project below the lower edge of trigger pin guide 41'. As the device of my invention is lowered over a section of drill pipe, the upper edge of the tubular member abuts against the lower tapered edge 35 of slips 28 thereby positioning the device to permit further downward movement with lips 31 in sliding contact with surface 34 of tubular member 32. When the elevator has been moved downwardly to a point where lip 3| of slips 28 is adjacent to or just slightly below shoulder so of member 32, the upper edge of member 32 contacts the lower endof trigger pins 42 forcing said pins upwardly thereby causing large annulus E5 to move opposite ball groove 21 and permitting ball 44 to move into said large annulus. With ball 44 in the large annulus, slip bowl 20 is free to move downwardly and, as a matter of fact, does so move by virtue of the bias exerted by spring 24. In moving downwardly slip bowl 20 forces slip assembly A into a locked position with lips 3| in engaging contact with shoulder 30 of member 32. In this manner member 32 is grasped so that it may be suspended, as by applying a lifting force to ring member l6 of tension member F. When lifting force is applied to ring member l5 suspending assembly D moves slidably along tension member F until end portion l8 of suspending assembly D abuts against ring l4 which is mechanically aflixed to tension member F. When this lost motion is taken up, further application of the lifting force will suspend tubular member 42.

When it is desired to release a suspended member, such as member 32, a fluid under pressure, such as compressed air, is supplied to the annular space defined by the lower edge of piston 2| and the upper edge of spring retaining member 23 through port H from a source, not shown. As fluid is so introduced, the downward pressure exerted by spring 24 is overcome and piston 2| is forced upwardly, causing piston guide 22 to move slidably along tension member F and thereby liiting slip bowl 20 from its position in contact with slip assembly A. With slip assembly A no longer forced by slip bowl 20 to assume its engaged state, slip assembly A assumes its expanded disengaged state as shown in Fig. 2. In its expanded state slip assembly A is out of contact with shoulder 30 of member 32 and the entire device may be lifted so that its lower end may become clear of the disengaged member 32. As member 32 becomes disengaged from'slip assembly A, trigger ring 39 is driven downwardly by trigger spring 43 and trigger pins 42 are again forced into a position such that their lower ends extend below trigger pin guide 41'. At the same time trigger balls 44 move into the space defined by small annulus 46 and ball groove 21, thereby locking slip bowl 20 against further downward or upward "movement until the device is again employed as described. It will thus be seen that the disengagement of my device from a tubular member also places the device in a condition for immediate use in engaging the next tubular member to be suspended. The process of engaging, suspending and disengaging pipe sections may be repeatedly accomplished without the necessity of exerting manual eilfort other than that involved in manipulating valves.

The lost motion in suspending assembly D is provided for the purpose of facilitating the use of the engaging and disengaging mechanism. Such an assembly is very useful and'when the device is employed for suspending sections of drill pipe, it is virtually necessary for practical employment thereof. Ordinarily a driller cannot be expected to lower a travelling block suspended from a drilling line and to bring it to a stop at exactly the desired point. Normally, the most that can be expected is that the driller bring the travelling block, and consequently the elevator suspended therefrom, to a stop at a point within a foot or two of the desired level. It is for this reason that the lost motion travel in the suspending assembly should normally be about two feet although it will be obvious that more or less travel may be provided as desired.

It will be obvious that various modifications may be made in the device of my invention as disclosed herein without departing therefrom. For example, in Fig. 4 I have shown a slip assembly which is composed of four slip segments with four intervening rubber segments. It will be obvious that as few as two may be employed while on the other hand the assembly may be divided into as many segments as desired. It will also be obvious that an operable device containing less than four, including a single trigger rod, could be constructed while on the other hand a much greater number than four may also be employed. I have shown four trigger rods in Fig. 5 inasmuch as at least four will insure operation of trigger assembly E at the intended time.

What I claim is:

1. A device for engaging with and suspending a tubular member having an upper end provided with an outwardly extending shoulder comprising, in combination, a body, a tension member adapted for suspension and mechanically connected to said body, a slip assembly disposed within said body and adapted for radial expansion and contraction and for engaging when contracted with the outwardly extending shoulder of said tubular member, means within said body slidably arranged with respect to the slip assembly and adapted to assume a first position allowing the slip assembly to expand and a second position contracting the slip assembly, a biasing member arranged to cooperate with said means to bias it to its second position, a piston member mechanically connected to said means arranged to move said means from its second position to its first position, and a trigger mechanism carried by said tension member arranged to cooperate with said means normally to maintain said means in its first position and to permit said means to move to its second position when said slip assembly is brought into operative relation with said tubular member for engagement with said shoulder.

2. A device for engaging with and suspending a tubular member having an upper end provided with an outwardly extending shoulder comprising, in combination, a body, a tension member adapted for suspension and mechanically connected to said body, a slip assembly disposed within said body and adapted for radial expansion and contraction and for engaging when contracted with the outwardly extending shoulder of said tubular member, a slip bowl disposed within said body slidably arranged with respect to the slip assembly and adapted to assume a first position allowing the slip assembly to expand and a second position contracting the slip assembly, a spring member arranged to cooperate with said slip bowl to bias it in its second position, a piston member mechanically connected to said slip bowl arranged to move the slip bowl from its second position to its first position, and a trigger mechanism arranged to cooperate with said slip bowl normally to maintain said slip bowl in its first position and to permit the slip bowl to move to its second position when said slip assembly is brought into operative relation with said tubular member for engagement with said shoulder.

3. A device for engaging with and suspending a tubular member having an upper end provided with an outwardly extending shoulder comprising, in combination, a body, a tension member adapted for suspension connected to and extending into said body, a slip assembly disposed within said body and adapted for radial expansion and contraction and for engaging when contracted with the outwardly extending shoulder of said tubular member, a slip bowl having a locking means on its inner surface disposed within said body and slidably arranged with respect to the slip assembly and adapted to assume a first position allowing the slip assembly to expand and a second position contracting the slip assembly, a spring member arranged to cooperate with the slip bowl to bias it to its second position, a piston member mechanically connected to the slip bowl arranged to move the slip bowl from its second position to its first position, and a trigger assembly mounted adjacent said tension member and said slip bowl adapted to engage with the locking means carried by said slip bowl normally to maintain said slip bowl in its first position and adapted to disengage from said locking means to permit the slip bowl to move to its second position when said slip assembly is brought into operative relation wtih said tubular member for engagement with said shoulder.

4. A device for engaging with and suspending a. tubular member having an upper end provided with an outwardly extending shoulder comprising, in combination, a body, a tension member arranged for suspension connected to and extending into said body, a slip assembly disposed within said body and adapted for radial expansion and contraction and for engaging when contracted the outwardly extending shoulder of said tubular member, a slip bowl defining an annular groove on its inner surface disposed within said body and slidably arranged with respect to the slip assembly and adapted to assume a first position allowing the slip assembly to expand and a second position contracting the slip assembly, a spring member arranged to cooperate with the slip bowl to bias it to its second position, a piston member mechanically connected to the slip bowl arranged to move the slip bowl from its second position to its first position, a trigger ring having downwardly extending pins arranged to be exposed to contact with the upper end of a tubular member when the slip assembly is in its expanded state, the said trigger ring defining an annular groove in its outer surface, the upper portion of said groove being shallower than the lower portion, a. spring in contact with said trigger ring to bias the trigger ring downwardly, a plurality of balls disposed in the annular groove in said trigger ring arranged to fit into the upper portion of said groove and in the annular groove defined by the inner surface of the slip bowl to maintain the slip bowl in its first position and arranged to move into the lower portion of said groove on abutment of said pins on the upper surface of a tubular member brought into operative relation with said slip assembly to permit the slip bowl to move to its second 10 position.

MARTIN E. TRUE.

No references cited. 

